#include <stdio.h>
#include <stdlib.h>
int main(){
  int i, n, a, b, c = 10000000;
  scanf("%d", &n);

  if(n) scanf("%d", &a);
  for(i = 1; i < n; i++){
    scanf("%d", &b);
    if(a != b && abs(a - b) < c)
      c = abs(a - b);
    a = b;
  }
  if(c == 10000000) c = 0;
  printf("%d\n", c);
  return 0;
}